Wheeled luggage has been popularly used in recent years by travelers in either airplane or any other forms of traveling. In the development of a wheeled luggage, several important and desirable characteristics must be satisfied. First, the luggage needs to be rigidly constructed and to have sufficient rigidity to survive rough handling on the streets, in and out of buildings having ascending or descending steps, and in and out of various forms of carriers such as a motor vehicle, a train or an airplane. Secondly, the wheeled luggage should have adequate wheel means such that a traveler can pull a luggage along on a pavement or other surfaces with relative ease. Thirdly, the wheeled luggage should have a convenient handle system such that it can be stowed securely when not in use.
Wheeled luggage available in the market today do not have reliable means for locking or unlocking a handle system. This creates problems when the luggage is being shipped and handled, for instance, at an airport. When the luggage is positioned sideways or in an upside-down position, the gravity of the handle may extend the handle such that various problems can occur such as damages caused to an automated luggage conveyor system. Efforts have been made by others to remedy the problems. For instance, in U.S. Pat. No. 5,526,908, a retractable handle assembly which can be easily expanded and folded without exerting a large force thereon. The retractable handle assembly includes a hollow bracket mounted on a top plate of one of the half bodies thereof, a pair of lug portions each formed on one of the distal end portions of the bracket and each having a first bore laterally defined therein, a pair of outer tubes each securely mounted between the lug portion and a bottom plate of the half body and each having a second bore laterally defined therein for aligning with the first bore, the pair of inner tubes each is slidably mounted in one of the outer tubes and each having a third bore laterally defined therein for aligning with the second bore, a substantially U-shaped handle portion mounted on the bracket and having two free end portions each engaged with the upper end of a corresponding one of the inner tubes, a pressing member movably mounted in a hollow bracket and including a knob extending through an opening of the hollow bracket, a biasing member mounted on an underside of the present member and including a pair of stubs each respectively extending through the first bore of associated lug portion, the second bore of associated outer tube and the third bore of associated inner tube.
In another issued U.S. Pat. No. 5,499,426, a handle device is disclosed which includes a pair of storage tubes adapted to be mounted on a rear face of a wheeled suitcase, a seat frame, a handle member and a locking mechanism. The locking mechanism is provided in the receiving space of the seat frame and includes two projecting members, a biasing unit between the projecting members for biasing the projection members toward the storage tubes and for locking the handle member relative to the storage tubes when the two engaging holes are in alignment, and a retracting unit for retracting the projecting members to release the handle member relative to the storage tubes. U.S. Pat. No. 5,431,428 discloses a carrying case assembly that is equipped with a collapsible handle assembly disposed within the case, the handle assembly includes a push button which allows the handle to collapse within the case. The handle assembly further includes a lock means for holding the first handle portion in an extended position relative to the second handle portion, the handle lock means includes a selectably releasable handle-locking protrusions on one of the first and second handle portions, movable in opposing directions toward and away from the other of the first and second handle portions into and out of engagement therewith. In still another issued patent, U.S. Pat. No. 5,502,876 a pull handle for a trunk is disclosed which includes a pair of driving rods each having a wedge member disposed at the bottom end thereof and is in abutment with a spring biased locking seat having an oblique cam surface. Each driving rod is housed in a hollow tube and the locking seat is in selective engagement with one of a plurality of spaced retaining slots disposed on a movable sleeve which accommodates each hollow tube.
Referring initially to FIG. 1 where it is shown a conventional retractable handle system 10. The retractable handle system 10 consists of two parallel supporting tubes 12 and a grip 14. The support tube 12 each has a tubular opening 16 for accepting a sliding tube 22. At the upper end of the support tube 12, an aperture 18 is provided for engaging a locking device 24 fixed to the end of the sliding tube 22 through a retractable locking pin 26. The grip 14 consists of a housing grip 20 connected to the sliding tubes 22 which slidingly engaging the tubular openings 16 inside the support tubes 12. At the end of each sliding tubes 22, a locking device 24 is provided which includes a locking pin 26 for locking the grip 14 and the two sliding tubes 22 onto the support tubes 12 through apertures 18. At the center of the grip 20, a push button assembly 28 is provided for controlling the locking devices 24 mounted at the end of the sliding tubes 22. When the push button device 28 is compressed downwardly toward the support tubes 12, it causes the retraction of the locking pins 26 away from the apertures 18 such that the sliding tubes 22 may freely slide in the tubular openings 16 of the support tubes 12.
A perspective view showing the components of grip 14 for the conventional handle assembly 10 of FIG. 1 is illustrated in FIG. 2. The internal structure of the push button device 28 is also shown. The grip housing 20 is constructed by an upper half 38 and a lower half 40. The upper half 38 of the grip housing 20 is provided with an opening 42 for housing the push button 34. The lower half 40 contains a cavity 44 and a shaft 46 affixed to the center of the cavity. The push button device 28 includes a push button 34, a spring 48 and two sliding blocks 36. The push button 34 is fitted to and can move freely upwardly and downwardly through the opening 42 in the upper half 38 of the grip housing 20. The spring 48 is installed on the shaft 46 for supporting the push button 34 such that the top of the push button 34 protrudes over the opening 42. The sliding blocks 36 are installed in the cavity 44 in the lower half 40 and are allowed to move in a longitudinal direction of the grip housing 20. Each of the sliding blocks 36 having an end close to the shaft 46 that is equipped with an inclined surface 50. The other end of the sliding block 36 is connected to a drive device 30. The bottom of the push button 34 is also equipped with two inclined surfaces 56 which engage the inclined surfaces 50 on the two sliding blocks 36 when the push button 34 is compressed downwardly. The engagement between the inclined surfaces 56 and 50 forces the two sliding blocks 36 to move inwardly toward the shaft 46. The inward movement of the sliding blocks 36 causes the drive means 30 to also move inwardly such that the locking device 24 connected to the bottom end of the drive device 30 can be released.
As described above, the operation of the conventional push button device 28 depends entirely on the engagement of the two inclined surfaces 56 situated on the bottom of the push button 34 with the two inclined surfaces 50 situated on the two sliding blocks 36 such that the two sliding blocks 36 are pushed inwardly toward shaft 46 when the button 34 is pressed down. One obvious disadvantage of the system is that when the force applied on the push button 34 is not uniform, the resulting sliding motion of the two sliding blocks 36 situated in cavity 44 is sluggish. This can cause the jamming of the push button 34 in the opening 42 when it is pressed downwardly into the opening at an angle. The non-uniform force applied on the push button 34 may also result in the locking devices 24 located at the bottom end of the two sliding tubes 22 not being unlocked simultaneously. These phenomena causes great inconveniences in utilizing the push button device 28 and furthermore, may cause damage to the device due to the non-uniformly applied forces on the push button 34.
It is therefore an object of the present invention to provide a push button device for releasing a locking mechanism that does not have the drawbacks or the shortcomings of a conventional push button device.
It is another object of te present invention to provide a push button device for releasing a locking mechanism by engaging a push button with a pair of sliding blocks aided by a gear wheel and gear surfaces located on the blocks for improved releasing action of the locking mechanism.
It is a further object of the present invention to provide a push button device for releasing a locking mechanism by engaging a gear wheel with gear surfaces located on a pair of sliding blocks into a rack-and-pinion motion to improve the synchronized action in pulling a pair of drive cables for releasing two locking mechanisms.
It is still another object of the present invention to provide a retractable handle system for a wheeled luggage equipped with a push button device for releasing a locked handle that has an improved operation than a conventional retractable handle system.
It is yet another object of the present invention to provide a retractable handle system for a wheeled luggage equipped with a push button device for releasing a locked handle by utilizing a gear wheel to engage gear surfaces on a pair of sliding blocks that moves in a rack-and-pinion motion for improving the releasing of the locked handle.
It is another further object of the present invention to provide a retractable handle system for a wheeled luggage that is equipped with a releasing device for the handle that does not require the use of a push button.